| Witham to Olympia Heights (Florida) | 4,465.48 mi (7,186.49 km) |
| Witham to Omaha (Nebraska) | 4,307.79 mi (6,932.72 km) |
| Witham to On Top of the World Designated Place (Florida) | 4,375.85 mi (7,042.26 km) |
| Witham to Onalaska (Wisconsin) | 4,005.01 mi (6,445.44 km) |
| Witham to Oneida (New York) | 3,449.95 mi (5,552.17 km) |
| Witham to Oneonta (New York) | 3,452.95 mi (5,556.98 km) |
| Witham to Ontario (California) | 5,431.91 mi (8,741.82 km) |
| Witham to Ontario (Oregon) | 4,844.89 mi (7,797.10 km) |
| Witham to Opa-locka (Florida) | 4,453.02 mi (7,166.44 km) |
| Witham to Opelika (Alabama) | 4,324.88 mi (6,960.22 km) |
| Witham to Opelousas (Louisiana) | 4,701.50 mi (7,566.33 km) |
| Witham to Orange (California) | 5,452.30 mi (8,774.63 km) |
| Witham to Orange (Texas) | 4,788.69 mi (7,706.65 km) |
| Witham to Orange City (Florida) | 4,342.96 mi (6,989.32 km) |
| Witham to Orangeburg (South Carolina) | 4,100.46 mi (6,599.05 km) |
